1. Field of the Invention
The present invention relates to a safety binding for a ski adapted to maintain the front of a boot mounted on a ski.
2. Description of Background and Relevant Information
Safety bindings of this type, also known as "Front Abutments", generally comprise a body containing an energy generating mechanism acting on a retention jaw mounted on the rear portion of the body of the front abutment. In certain front abutments, the jaw is constituted by two independent lateral retention wings, journalled respectively on the body, around independent axes, and which are positioned symmetrically with respect to the vertical and longitudinal plane of symmetry of the front abutment. The lateral retention wings are biased elastically, by the energy generating mechanism contained in the body, in the direction of the plane of symmetry of the front abutment in a manner so as to squeeze the front of the boot between them. Such front abutments are described, for example in French Patent No. 2,210,422 and Swiss Patent No. 509,810.
During the mounting of a boot on the ski provided with such a front abutment and a rear heel binding maintaining the rear end of the boot, the sole of the boot which is engaged longitudinally towards the front between the two lateral retention wings of the front abutment, pushes these two wings towards the exterior. In the course of this movement the edge of the sole first comes into point contact, on each side, with a lateral roller which is rotationally mounted on the corresponding wing around a vertical axis and which projects with respect to the internal surface of this wing. This roller can if desired be replaced by a projection or bump formed on the internal surface of the wing. With such a construction, as soon as the lateral retention wing tends to move away from its rest position or is in the release position, in which it is relatively close to the vertical and longitudinal plane of symmetry of the front abutment, it exerts, on the edge of the sole which forces it to pivot towards the exterior, a substantial reaction force towards the rear produced by the energy generating mechanism positioned in the body of the binding. The direction of application of this reaction force is thus slightly inclined with respect to the longitudinal axis of the ski and this reaction force is almost totally in opposition to the force exerted towards the front, on the body of the heel binding, the return spring being housed therein. As a consequence, during mounting of the boot, the boot barely opens the front of the lateral retention wings, which are then strongly squeezed by the energy generating mechanism of the front abutment, and on the contrary the positioning and the immobilization of the boot, in the engaged position, occurs only at the expense of a slight retraction of the body of the heel binding against the action of the return spring, which causes a lowering of the release force.